Improving the Dynamic Performance of the Crank-Rocker Mechanism Using Composite Links

In practice, the transmission angle is a crucial factor for reducing the required driving power and improving the dynamic performance of the mechanisms and machines. The vibration of elastic links is unavoidable in mechanisms running at high speeds. Thus, optimum link lengths decrease driving power since they ensure optimal transmission angles. In addition, joints made of hybrid and nonhybrid composites are lightweight and require less driving torque. Additionally, composite links can be used in place of metal links to alleviate wear and corrosion issues. Through the use of composite links, the dynamic performance of the mechanism and the machine will be improved as a result of the higher damping factor, stiffness, and flexural modulus values of the composite materials. Accordingly, this research considers the effect of transmission angle, four case types of linkages proportions, and stacking sequences on the natural frequencies and instability thresholds of the mechanisms. Therefore, the finite element method (FEM) was used to efficiently compute the Eigen-nature for the mechanisms with composite links. The experimental tests are also conducted using the frequency response function method (FRF). Based on the results, the CR mechanism performs best at 90° of the transmission angle, as the average natural frequency of this angle decreases by 11.19 % and 26.17 % compared to the maximum and minimum transmission angles. Overall, the measuring and theoretical fundamental response frequencies of mechanisms are in good agreement.